The cookie npm package simplifies HTTP cookie handling in Node.js. It provides utilities for parsing, serializing, and managing cookies received in HTTP requests and sent in HTTP responses. With cookie, you can easily extract cookie values, set new cookies, and control attributes like expiration, path, and security flags. It streamlines cookie interactions within web applications and simplifies tasks like session management and user authentication. The library's straightforward API makes it convenient for both small and large projects requiring robust cookie functionality.